Tournament Play
What blinds and antes are actually for
Forced bets exist to make a hand worth contesting. Rising forced bets exist to make a tournament end.
Blinds and antes are wagers nobody chooses to make. They are posted because the rules say so, before any cards are looked at, and they do a specific structural job.
Consider a game without them. With nothing in the middle, the correct approach for every player is to wait for a very strong hand and pass on everything else. Since that is true for everyone at once, nothing happens. There is no reason to contest a pot worth nothing.
A forced bet removes that equilibrium. Once there is something in the middle, passing has a cost and contesting has a reward, and play begins. That is the whole mechanism.
Blinds do this positionally. One or two seats immediately left of the dealer button post a fixed amount before the deal, and the obligation moves round the table one seat per hand so that everyone carries it equally over a full orbit.
Antes do it collectively. Every player contributes a small amount to the pot, or in the common modern arrangement one seat posts a single larger ante on behalf of the table. Either way the starting pot grows without changing whose turn it is to act.
In a tournament the levels rise on a schedule, and that turns the forced bet into a clock. A stack that plays no hands still loses ground every orbit, and the ratio between a stack and the current blind is the number that governs decisions late in an event.
This is what forces a tournament to finish. Without rising levels a large field could persist indefinitely. With them, the cost of an orbit eventually approaches the size of the remaining stacks, and the event resolves.
In a cash game the blinds are fixed and none of this applies. They still generate action, but they never escalate, which is why the same nominal game plays quite differently in the two formats.